View Full Version : GAP Tool speedo correction
loanrangie
21st December 2022, 01:11 PM
Since moving up tyre sizes to 265/65/18 i have have my speedo to under read by 1-3kph which i'd like to correct so it reads a similar amount as per original, i haven't looked on the app yet to see how its done but is it by changing the diameter or circumference ?
Redtail
21st December 2022, 01:15 PM
I set mine to be more accurate, but the menu steps would be the same ...
Speedo calibration with IIDTool? (https://www.aulro.com/afvb/electronic-diagnostic-systems/262612-speedo-calibration-iidtool.html)
loanrangie
21st December 2022, 01:22 PM
Never mind, a quick google found the answer.
John_D4
21st December 2022, 01:38 PM
I adjusted my Speedo to be bang on, but my odometer is out by the 5% that I adjusted my Speedo by. I can’t find a fix for it
loanrangie
21st December 2022, 02:59 PM
I adjusted my Speedo to be bang on, but my odometer is out by the 5% that I adjusted my Speedo by. I can’t find a fix for it
I came across a forum that mentioned that and the fix, pretty sure its in this thread - Speedometer recalibration with IID Tool | Land Rover and Range Rover Forums (https://www.landroverworld.org/threads/speedometer-recalibration-with-iid-tool.42247/)
John_D4
21st December 2022, 03:55 PM
I came across a forum that mentioned that and the fix, pretty sure its in this thread - Speedometer recalibration with IID Tool | Land Rover and Range Rover Forums (https://www.landroverworld.org/threads/speedometer-recalibration-with-iid-tool.42247/)
I’ll try that. Thanks
loanrangie
23rd December 2022, 07:35 PM
Adjusted the radius to 401mm after finding the radius for this size is 400.85mm, at 80 GPS read 77 so will see how out it is at 100 and maybe go down to 400mm.
peterjj
24th December 2022, 09:01 AM
My MY08 RRS IID tool seemed only to allow tyre radius setting. I could only get speed OR odometer correct, not both at the same time. I had to experiment with radius setting as entering the actual tyre radius didn't result in anything correct. I chose correct odometer and added a GPS HUD for correct speed.
I also noted looking at the live values in IID tool that shows a speed value more accurate than what the instrument cluster does.
loanrangie
24th December 2022, 09:21 AM
My MY08 RRS IID tool seemed only to allow tyre radius setting. I could only get speed OR odometer correct, not both at the same time. I had to experiment with radius setting as entering the actual tyre radius didn't result in anything correct. I chose correct odometer and added a GPS HUD for correct speed.
I also noted looking at the live values in IID tool that shows a speed value more accurate than what the instrument cluster does.I didn't look at other settings but assumed the correlation between Speedo and odometer would change as well.
 D3 only has basic settings unlike the D4.
Powered by vBulletin® Version 4.2.4 Copyright © 2025 vBulletin Solutions, Inc. All rights reserved.